"It's too difficult to give an exact number because that is constantly changing. A lot of teachers who took the language proficiency exam between 1992 and 1999 still do not meet requirements," Tomusk told ERR.

Tomusk asserted that competence in the official state language is an essential professional requirement for schoolteachers. He argued that employers should not hire those who do not meet professional standards, and concerning school staff, substandard language skills may be sufficient grounds for dismissal.

"The language inspectorate can issue written orders, but we do not have the authority to discharge people from work. Therefore, we can't monitor how many teachers are let go because of inadequate language skills," Tomusk said. "Some of the Russian-language schools in Tallinn and Ida-Viru County are showing weak results in teaching Estonian. However, the situation is gradually improving."

The nationwide overhaul for Russian-curriculum high schools to adopt an extensive Estonian-language program began in 2007. Beginning in the 2011/2012 school year, Russian-curriculum high schools are required to teach 60 percent of their material in Estonian. Subjects include Estonian literature, social studies and music.

Tomusk added that many teachers have received additional training in connection with the overhau